/Engine/Source/Runtime/Engine/Classes/Animation/AnimMontage.h
Simulate is same as Advance, but without calling any events or touching any of the instance data. So it performs a simulation of advancing the timeline.
bool SimulateAdvance ( float DeltaTime, float & InOutPosition, struct [FRootMotionMovementParams](API\Runtime\Engine\Animation\FRootMotionMovementParams) & OutRootMotionParams ) const